Why Passive House?
With the considerable technological advances witnessed and the drive to achieve Passive House sustainability levels, Spitfire front door design has been hugely improved over the last 5 years and we thought it time to update our advice on thermal values.
The UK government’s Energy Saving Trust claims that external doors often account for up to 20% of the heat lost from a home. So, with energy costs only going one way, there is even more reason to fit a Spitfire Door, which in the long run will save you money. And you can be kinder to the planet for future generations to enjoy by selecting a door that could meet Passive House targets.
What we have discovered is that Architects often design Passive House Homes, but the cost of testing the whole house to prove conformance can be cost prohibitive and most people compromise by fitting the best thermally efficient products available, but fall short of overall Passive House certification, because they don’t pay for the whole house testing. To us, that seems a reasonable compromise.
We know that front doors that have extremely low U values easily outperform inferior composite doors which have poor U values, at 1.4 W/m2K or worse. The U value of a door is very important if you want to keep your home warm in winter and reduce your carbon footprint. Spitfire Front Doors easily achieve ratings lower than the Passive House trigger level of 0.8 W/m2K. Even our entry level Spitfire S-100 aluminium doors beat this standard.
Get in touch to find out more.
How U Values work
U values measure the rate at which heat is transferred through a material, within a given period of time. The lower the U value, the better the material is at preventing heat loss, known as the thermal conductivity performance. Design your Passiv Haus front door here
The U value of a front door can be affected by several factors, particularly the materials used, the door thickness and the glazing.
The levels achieved by materials :
Standard timber doors: 1.8–2.0 W/m²K.
- Spitfire timber doors: 0.8 W/m²K.
- Modern composite or GRP/Plastic doors: 1.2–1.4 W/m²K.
- Standard steel doors: 1.8–2.0 W/m²K.
- Spitfire Alu-Steel doors: 0.77 W/m²K
- Spitfire Passive House level doors: ≤0.8 W/m²K
Door Thickness
The depth or thickness of a door is very important in helping to achieve excellent thermal insulation. Deeper door panels usually have lower U Values as they are better insulated, having more space to hold high-density foam. Spitfire Doors vary from 65mm to 115mm thick depending on the door series and thermal requirements stipulated. A typical timber or composite door is only 48mm thick.
Glazing
Triple glazing is preferable in a front door because that also helps reduce thermal transference. Spitfire Doors are all triple glazed with laminated safety glass and the sealed units are filled with Argon, which further enhances the performance. Standard timber and Composite doors are not thick enough to accommodate triple glazing, which drastically reduces their thermal performance.
Thresholds and Weatherseals
Spitfire Doors feature very quality high-quality thresholds and weatherseals, designed where high performance and Passive House is desired.
Front Door Installation
The key area that is often overlooked is installation. Even the best designed and manufactured door will perform poorly if fitted badly. Spitfire recommends that all doors are fitted by authorised Spitfire Doors Partners across the UK and Ireland. Installation is critical because a badly installed door will not perform well if it is badly fitted and that is why we always recommend you use Spitfire Doors or Spitfire Doors approved installation partners. This is even more critical in Passive House situations.
Building Regulations
In the UK, Building Regulations stipulate that external doors must meet several standards. The maximum (or worst) U Value for an external door in a new build or a significant renovation is 1.4 W/m²K, in Scotland it is 1.2. That is the minimum requirement and if you want to significantly increase the performance of your door aim for 0.9 W/m²K or lower. Get in touch with Spitfire Doors
Assurance
By choosing a front door with a low U Value, you will reduce your energy bills, improve the comfort of your home and contribute to a more sustainable future.
Rest assured that all Spitfire Doors conform to and easily beat Building Regulation requirements and we have doors that achieve as low as 0.6 W/m²K, if required.
Please contact us if we can help or advise you in any way.
You are very welcome to visit our Flagship Showroom in Macclesfield, Cheshire. To give you the best possible experience and to ensure we can show you the full range of doors, please make an appointment prior to your visit – call 01625 412570 or email enquiries@spitfiredoors.co.uk. We look forward to hearing from you.